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/* Copyright (C) 1991, 1992, 1993, 1994, 1995 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public License as
published by the Free Software Foundation; either version 2 of the
License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Library General Public License for more details.
You should have received a copy of the GNU Library General Public
License along with the GNU C Library; see the file COPYING.LIB. If
not, write to the Free Software Foundation, Inc., 675 Mass Ave,
Cambridge, MA 02139, USA. */
#include <ansidecl.h>
#include <unistd.h>
#include <hurd.h>
#include <hurd/paths.h>
#include <fcntl.h>
#include <string.h>
/* Read the contents of the symbolic link FILE_NAME into no more than
LEN bytes of BUF. The contents are not null-terminated.
Returns the number of characters read, or -1 for errors. */
ssize_t
DEFUN(__readlink, (file_name, buf, len),
CONST char *file_name AND char *buf AND size_t len)
{
error_t err;
file_t file;
char mybuf[2048], *transp = mybuf;
mach_msg_type_number_t translen = sizeof (mybuf);
file = __file_name_lookup (file_name, O_NOTRANS, 0);
if (file == MACH_PORT_NULL)
return -1;
err = __file_get_translator (file, &transp, &translen);
__mach_port_deallocate (__mach_task_self (), file);
if (err)
return __hurd_fail (err);
if (translen < sizeof (_HURD_SYMLINK) ||
memcmp (transp, _HURD_SYMLINK, sizeof (_HURD_SYMLINK)))
/* The file is not actually a symlink. */
err = EINVAL;
else
{
/* This is a symlink; its translator is "/hurd/symlink\0target\0". */
if (len >= translen - sizeof (_HURD_SYMLINK))
{
len = translen - sizeof (_HURD_SYMLINK);
if (transp[translen - 1] == '\0')
/* Remove the null terminator. */
--len;
}
if (buf == NULL)
/* This call is just to find out how large a buffer is required. */
len = translen - sizeof (_HURD_SYMLINK) - 1;
else
/* Copy into the user's buffer. */
memcpy (buf, transp + sizeof (_HURD_SYMLINK), len);
}
if (transp != mybuf)
__vm_deallocate (__mach_task_self (), (vm_address_t) transp, translen);
return err ? __hurd_fail (err) : len;
}
weak_alias (__readlink, readlink)
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